The present invention, in some embodiments thereof, relates to drug delivery systems and, more particularly, but not exclusively, to apparatuses and methods for securing components of a drug delivery system during assembly and/or transport.
Failure to use a delivery device or system, such as an insulin pen or auto-injector, correctly could result in a life or death emergency, or impact a patient's or caregiver's ability to manage a medical condition effectively. For the pharmaceutical manufacturer, such a failure could result in a massive backlash that may cause loss of market share, costly product recalls or worse.
The primary goal of any drug delivery system is to ensure that a patient receives a proper dose of a prescribed drug. In years past, if a device failed or was used incorrectly, patient or caregiver error was most often the culprit. While providing detailed instructions is important for any pharmaceutical manufacturer, failure to follow directions is no longer a viable excuse when a patient or caregiver is unable to operate a device or delivery system successfully.
Effective drug therapy and treatment typically involves more than simply having an effective molecule. Rather, it is the combination of a safe drug within a suitable container and/or delivery system.
Historically, pharmaceutical manufacturers have focused, and rightly so, on the efficacy and safety of the drug product. However, if the drug is to achieve its therapeutic objective, then its primary container and delivery system must be both compatible with the drug and stable over time, as well as foster adherence from the patient. A drug can only truly have the desired patient benefit if it is taken as prescribed, delivered effectively (often by a patient or caregiver), and maintains performance over time.
Today's injectable therapies can take many forms. Liquid drugs may use a traditional syringe and vial; a prefilled syringe; or a delivery system such as an auto-injector, pen device or patch injector. Lyophilized drug products (requiring reconstitution with water for injection) may use a kit containing a transfer device, syringe or needle, and containers of the drug and water.
The container format itself also should be considered. Vials may be used for initial use, but a syringe or cartridge system may provide the best solution for the patient when the system reaches the market. Once the primary container has been selected, efforts must be made to ensure that it works with the delivery system. Dimensional tolerances and functionality should be tested to ensure proper activation and gliding forces.
Recognizing how the patient or caregiver interacts with the delivery system is essential to ensuring success in the market. Even the most innovative drug can provide the appropriate therapeutic benefit to the patient only if it can be delivered effectively and the patient adheres to the treatment regimen. Patients or caregivers may choose one product over another based on dose frequency, pain associated with dosing, or ease of use or mobility of the delivery system. Simply put, packaging can differentiate a product's market acceptance.
One frequent ease of use issue that is encountered by users of drug delivery systems, for example patch injectors like the SmartDose® Electronic Patch Injector System offered by Medimop Medical Projects Ltd., a subsidiary of West Pharmaceutical Services, Inc., is movement of the operative parts during transport. For example, vibrations during transport may cause movements of screws causing a telescoping assembly (TSA) of the delivery system to extend. As result, when a cartridge containing the unintentionally extended telescoping assembly is inserted by the user, it may be difficult to close the door of the delivery system. Some users may interpret this as a malfunction and elect not use the unit.
International Patent Application Publication No. WO/2011/090956, the disclosure of which is incorporated herein by reference, describes a cartridge interface assembly characterized by a driving plunger including an outer shaft, and a driver including an inner shaft movable telescopically with respect to the outer shaft, wherein rotation of the driver causes the driving plunger to advance in a direction away from the driver. When the cartridge interface assembly is inserted in a cartridge in which a plunger is slidingly disposed, rotation of the driver causes the driving plunger to advance distally in the cartridge until abutting against the plunger. The shafts may tend to unscrew during transportation and handling before assembly, with the result that the position, which is the desirable position for assembly with the cartridge plunger, is not maintained. On the other hand, if the driver is tightened too much against the body of assembly in an effort to maintain the closed position of this can increase the torque used by the motor to overcome the tight connection in order to start turning the driver, thereby overburdening the motor. To solve this double problem (possible opening of telescoping shafts or the driver being tightened too much), a locking assembly is provided